Heating and ventilating apparatus.



J. K. NORSTROM & G. C. BREIDERT. HEATING AND VENTILATING APPARATUS.

APPLICATION FILED NOV. 5, l9l3- 1,232,598. Patented July 10, 1917.

5 SHEETS-SHEET l.

J. K. NORSTROM & G. C. BREIDERT.

HEATING AND VENTELATING APPARATUS.

APPLICATION FILED NOV. 5.1913.

Patentefi July 10, 1917.

5 SHEETS-SHEET 2- J. K. NORSTROM & G. C. BREIDERT.

HEATING AND VENTILATING APPARATUS.

- APPLICATION FILED NOV. 5, 1913- 1,232,598. Patented July 10, 1917.

5 SHEETS-SHEET 3 n. m m u RNN Mm MM a ww J. K. NORSTROM 61 G. C.BREIDERT.

HEATING AND VENTILATING APPARATUS.

APPLICATION FILED NOV- 5,1913- J. K. NORSTROM & G. C. BREIDERT. HEATINGAND VENTILATING APPARATUS.

. APPLICATION FILED NOV. 51 1913. 1,232,598. Patented July 10, 1917.

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m Gear Gfireiderf unrrnn STATES PATENT onnrcn.

JOHN K. NORSTROM AND GEORGE C. BREIDERT, OF CHICAGO, ILLINOIS.

especially well adapted for use in street- HEATING AND VENTILATINGAPIEARATUS.

Specification of Letters gatent.

- Patented Jul 10, 191 "1.

Application filed November 5, 1913. Serial No. 799,276.

To all whom it may concern:

1 Be it known that we, JOHN K. NoRs'rnoM and GEORGE C. BREIDERT,citizens of the United States, all residing at Chicago, in the county ofCook and State of Illinois, have invented certain new and usefulImprovements in Heating and Ventilating Apparatus, of which thefollowing is a specification.

This invention relates to improvements in heating and ventilatingapparatus, and particularly to an automatically controlled system forelectric-heating and forced draft ventilating. v i

In some of itsfeatures our invention is railway cars, and we have shownherein an embodiment particularly designed to such use, but it will beunderstood that we donot limit our invention in its broader aspects tosuch installations In the system nowmost generally inuse for heatingstreet-cars, a series of heating coils are placed under the seats of thecar and thefcurrent turned on or cut ofi by the motor-man or conductorwhenever he thinks a change in the temperature of the car should bemade. It is a-well known fact that thissystem is most unsatisfactory as.it vdepends for its eiiiciency upon the care andattention given to it'by 'the operators.

' theheater element controllerzconstructed to provide a shiftable membermovable 1n op- In our improved. system we have provided for automaticheat control, thecontroller,

automatically governed in its movements by a thermostat, operating tostart or stop, if desired) a ventilating fan and acting to vary theheat-supply, as by cutting in o .out a'plurality of electric heatingcoils '90- sitioned within the delivery duct of the fan. A particularfeature of our invention is posite directions respectively, inresponseto a-thermostats response to rise and fall of temperature; toprovide. a positive lock for said shiftable member in eachpositlon, and.to govern the controlling circuit: for-its electro responsive devices sothat said. circuit is active only when the thermostat I re-= sponds totemperature changes.

A further featureof heating is the mounting'of the thermostat our1nvention.re'sides'- in the provision of an adequate thermo-re sponsiveapparatus for and-connections for governing the controller. 'Anotherfeature of our invention, especially relating to -c,ar-

and ventilated, whereby it is more responsive to temperature changes,thereby varying the heating capacity of the apparatus and preparing theinterior of the compartment, prior to its being actually afi'ected bythe outside change. A further feature of our invention relates to theelectrical heating installation, for provision of adequate,readily-variable heater, in association with an air duct to give minimumobstruction to air flow.

Whereas we have shown and described the apparatus as applied to a streetrailway car, it is obvious that it would'be equally efiicient when usedfor heating and ventilating dwelling houses, public. buildings or infact any compartment or'inclosure.

In the drawings, wherein we have illus trated a particular embodiment ofour invention,

Figure 1 is. a side elevation of a street railway car withparts brokenaway to show the installation of our apparatus.

Fig. 2 is a vertical longitudinal sectional view through the intake anddischarge duct of .our Ventilatin fan showing our improved heating coilsin position.

Fig. 3 is a perspective view of a heating unit.

Fig. 4. is a wiring diagram showing the and unlocking the slidablecarriage of the p controller.

Fig. 9 is a plan view of the relay.

Fig. lO is a plan view with parts broken away of ,our improvedthermostat.

casing broken away, and;

Fig. 12 is a fragmentary side elevation of Y the ratchet pawls raisedfor actuating the carriage. 1 p

{In .Fig. '1 is shown a street railway car Fig. 11 is a side elevationofthe thermo- .stat shown in Fig. 10 with parts of the 10 upon the floor11', on which is mounted a venti'lating fan 12 driven by an electric-motor 13. This is positioned at one end of a the car, 'the eye of thefanbeing connected with an intake duct 14 extending along the side ofthe car up at the opposite end at 15, extending through the roof, theopening being: provided with a grating or screen 16.

he delivery duct 17 leading from the fan extends from the dischargeopening 18,

7 along the, inner side of the inlet duct 14 bemginset therein so as tobe inclosed upon three of its sides. A plurality of openings 19 areprovided in the .duct 17 for the passage of the air out into the car.The inlet duct 14 preferably surrounds three sides of the outlet for theheated air, throughout its length, or particularly the length of theheater-containing area of said outlet duct, in order topartially warmthe air before its introduction into the fan. The outlet duct 17 for ashort distance from its connection with the outlet of the fan at 18 isenlarged as at 17' and within this enlarged sect" on are mounted aseries of heating coils 19' which serve to heat the air. as .itisdelivered from the fan into the car.

Whereas we have shown but a single ven-I tilating fan, together with itsinlet and discharge ducts, it is obvious that if such a fan hasnotsuflicient capacity to ventilate a car, a similar set may be mountedupon the opposite side of the car. adjacent to the floor withits inletopening running out of the opposite" end, from that with which theotherventivlatin set communicates, thus compensating for c anges indirection of car-travel.

The controller is indicated at 20 in dotted lines Fig; 1 as positionedin the roof of the compartment at one end of the car, the relay 21 beingmounted adjacent. We have found that it is of advantage to have thethermostat 22 positioned outside of the car so that it is su currentthrough a lead 24 connected to one terminal 25 of a generator 26, theother-terminal 27' of which is grounded at 28. A thermostat armindicated diagrammatically at 29, carrying at one end a spring presserroller 30 makes progressive contact. with aseries of points 31, 32, 33,34, 35, 36, 37, 38,

and 39. v The thermostat arm is pivoted on a pin and from its pivotalpoint a conductor 41 leads through a variable resistance 42 to thetrolley arm 43, the wheel 440i which p makes contact with thetrolleyline 23' The contact points 31 to 39 respectively arepositioned'in anarc described about the pivot pin 40 of the thermostatarm and since the wheel 30 is spring pressed in contactwith the points,it is obvious that the progressive movement upward and downward of thearm is in a series of jumps'or steps, the roller always occupying,except when in motion, a position between and in contact with ject tothe changes of temperature outside of, rather than inside of- I the car.In Fig. 4 is shown a wiringildiagram which 23 represents a trolley ereceiving 1 4 5 operation of two of the pins. Any slight changes in tem-[perature, such as would effect a sensitive i thermostat areinsuflicien'tto operate our improved thermostat, as its movement isresisted by the spring pressed wheel 30 until the change is suficient toforce the roller over one of the pins and into its next contactposition. I

The moving part of our controllercomprises a carriage or slide, 45"mounted in a frame and free to move backward or forward except ascontrolled by, the ratchet mechanism connected with the magnets 46, and47 The movements of this carriage are controlled by the thermostat,and'the carriage movement governs the operation of the heating devicesand the connections be tween the carriage-operating electro-responsivedevices and the thermostat. In order to clarify the wiring diagram thesliding car,-

riage is split into three parts showing in'the directly these magnetsare. controlled by respective relays, 54, 54 and the circuits for eachrelay is controlled by the thermostatic switch, 29, by switch mechanismon the slide itself (lowestsection) and by a switch 53 or 53 moved bythearmature of the respective carriage-moving magnet. This, in order thatthermostat movement, completing a relay circuit otherwise closed, maycause actuation of" the carriage-moving magnet, the

activity of which breaks the relay circuit to permit retraction of themagnet-armature, such armature retraction moving the carriage to kill,or open, the just-used connection from the thermostat and prepare thecarriage-movingdevices for appropriate response to a succeeding movementof the thermostat switch in either direction.

' Directly in "front of the adjacent ends of the cores of the magnets 46and 47 are slidablymounted the two armatures 48 and 48' normally heldaway from the magnets 'the' armature-connecting springs 49.

Ratchet pawls 50 and 50' are pivotally connected to' the armaturesandengage with oppositely disposed ratchet teeth 51 and 51" carried by theslide 45. Rods 52 and 52 are connected to the armature 48 and 48' and ontheir opposite ends they coact with the movable parts, of the switch 53,53.

It; is obvious that in the mechanism as shown in' the wiringdiagram,.movement of the carriage could not be obtained by the either ofthamagirets, owing to the locking effect-of the pawl on the othermagnet. We have provided howeve'rin our controller, which we will laterdescribe in detail, a mechanical release mechanism interconnecting thetwo pawls so that when one is moved backward over a tooth into positionto be advanced by the spring and move the slide, the other isautomatically disengaged to permit such movement.

Relays 54 and 54, operating switches 55 and 55 connected in series withthe respective magnets 46 and 47 are energized through the medium of thesliding contact bars 56 and 57 operating across the contact fingers 58,59, 60, 61, 62, 63 and 64.

On the side of the carriage opposite to that carrying the slidingcontacts 56 and 57 are mounted two contact strips 65 and 66 togetherwith pins 67 and 68 which pass through the carriage making contact atproper intervals with fingers on opposite sides thereof. On the upperside of the frame extending over the carriage are positioned the contactfingers 69, 70, 71, 72 and- 73 and on the lower tact fingers 74, 75, 76.

Before describing in detail the instrumen'talities whereby we obtain thevarious movements and control the various parts, we will first describethe general operation of side are mounted conthe system as illustratedin Fig. 4.

' and 32.

,nection no change takes place until the arm For convenient positions ofthe carriage the letters A, B, C, D and E are placed opposite the pointsoccupied by the right hand end of the carriage in its various positionsas moved forward or backward by the operation of the ratchet pawls 50and 50 upon the ratchet teeth 51 and 51. Considering the carriage at theextreme right hand position indicated by letter A as shown in thediagram, the first upward movement of the thermostat arm 29 due to adecrease in temperature, will bring the roller 30 in'contact with thepin 31. The pin 31 is connected by means of a wire 77 with the finger63. In-the position shown this finger 63 is out of contact with eitherof the slides 56 or 57 and no current will flow. As the temperaturecontinues to decrease the thermostat arm.29 will it occupies theposition between the pins 31 As the pin 32 has no outside con- 29 movesstill farther upward throwing the roller into position between pins 32and 33. Pin 33 isconne'cted by the lead 78 with contact finger 62 and asthis is in engagement with slide 56 current will flow through thefollowing circuit: from the line wire .23,

through trolley 43, resistance 42, over the wire 41, through the arm ofthe thermostat 29, to contact pin 33, through lead 78'to spring .finger,62, into the slide 56, out through the spring finger 58, through wires79 and 100 to swltch 53, over the wire 80 reference to the various moveforward until from the trolley 43, throu to relay magnet 54 and groundat 81. Cur-- rent flowing through this circuit energizes the relay 54,closing the switch 55. This magnet 47 through tooth of the ratchet 51and forcing the rod 52 back to open the switch 53. Opening the switch 53deenergizes the relay 54, consequently opening the circuit through themagnet 47 permitting the spring 49 to draw the armature 48 away from themagnet and move the sliding carriage to the left one step or notch. Thismovement throws the carriage with contact strip 56 to the left toposition B taking it away fromunder finger 62' and breaking the controlcircuit, killing the connection of thermostat-point 33. Current flowonly momentary. The contact 33-being now dead, no further advancemovement of the carriage can take place until thermostat arm 29 reachesthe next live contact 35. The carriage-movement, however, moves stripover to connect fingers 64-63. This potentiates the connection 77 forthe thermostat contact 31, which initially was dead as described, andprepares the electro-responsive devices to move the carriage.

back to initial position should thermostat arm 29 return to contact withpoint 31.'

to accomplish these results is fingers 71, 70 and 69,- respectively. The

other ends of X and Y are connected through wires 109 110 to fingers 75and 74 respectively, and t e opposite end of coil Z is connected throughwire 111 to wire 112 which is connected at one end to spring finger 76and at the other end to the wire 83 leading to the trolley.

The next upward step of the thermostat throws the wheel 30 into positionbetween the pins 33 and 34 without in any way effecting thecontroller.On a further decrease in temperature the thermostat arm will be thrownup another step until the wheel 30 is positioned between contact pin34-and 35. Current will instantly flow through h the. circuit 42, 41,40, 29, 30,35, wire 113, ger 61, slide 56, finger 58-, wire 79 andthrough the relay circuit previously traced to ground at 81.

Y The magnet 47' will then be energized through the circuit previouslytraced and the carriage moved to point C.- This carries the slide 56'out from under contact finger J 61- and breaks the operating circuit. onin this position the circuit for the heating coils will be as follows,the fan still remaining in circuit: from the trolley 43 through wires82, 83, 112,111, to coil Z, wire. 108, finger 69 through pin 67, springfinger 74,

wire-110, coil Y, wire 107, spring finger 7 0,

' pin 68, finger 75, wire 109, coil X, wire106,

spring finger 71, contact bar 65, wire 104 and to ground at ,105. Thefan circuit through wire. 103, slide 65, and wire 104v to ground 105remains closed.

Still further upward movement of the thermostat arm 29 brings the roller30 into engagement with the, contact point 37 causing current to flowthrough the wire 114 to. finger 60 and thence through the-relay circuitpreviously traced; This again energizes the magnet 47 causing thecarriage to move to the left another notch and into 'po-' sitionindicated at D. As this'movement is due to a lowering of the temperaturebutside'the car it isessential that greater heat. be radiated from thecoils X, and Z4to' maintain the interior of the 'car at a com-..

fortable temperature; '7 This motion of the carriage disconnects thecoils from seriesre lation and places colls Y. and Z 1n ser1es andthe'coil X directly across the line. This placing of the coils, two inseries and one in parallel will increase the heat radiated from thecoils and raise the temperature of the car, through the medium of theheated air .flowing through they delivery duct from' the fan. e

The next step up of the rheostat arm 29.

. causes the roller 30 to contact with the pin to be met where theapparatus is installed.

' slide, killing the It will be observed that each step of the v oint ofthe thermostat with which arm 29 hen coacts, cuts into potentialcondition: the formerly-dead contact of the thermostat previously passedby the arm 29, and it will be observed that .the slide 57 which'sopotentiatesthe passed contacts is connected with relay 54. Thuslwhilethe contact bar 56,.when the carriage is in .positionE, is ata pointwhere its-right hand end is betweenthe two spring fingers 58 and 59, andno current can flow through the wire 115, the contact bar 57 is now in aposition where it engages with contact fingers 60, 61, 62-, 63, and 64.With a rise in temperature the roller 30 will drop down away from thecontact 39 and make contact with pin 37. Current will then flow from thetrolley 43 to resistance 42, through wire 41, arm 29, roller 30, pin 37,wire 114, spring finger 60, slide 57 spring finger 64, wires 116 and 117through the switch 53, wire 118, into the relay 54, out through wire 119and to groundat 120., The relay 54 being energized causes the closure ofthe switch 55 permitting current to flow from trolley 43 through wires82, 121, 122 through the switch 55, wire 123, through magnet 46, out towire 124,-to ground at 125. Energizing the magnet 46 draws the armature48 against the resistance of the'spring 49, slipping the pawl 50 backover one of the ratchet teeth 51 and at the same time through the mediumof the rod 52 .breaking contact at the switch '53 and permitting-thespring to draw the carriage or slide one step to theright. Thisbringsthe slide back into the position indicated. at D and 'it isobvious that further movement of the thermostat arm 29 downward willcause subsequent steps or jumps of the slide to the right throughpositions C, B and "back to A.

At any intermediate point on the. downward travel should a change intemperature.

vcause the rheostat.-to reverse its movement the magnet at the oppositeend of the slide will be energized and the carriage thrown back one stepthrowing the coils into the position occupied prior to the last step.

The apparatus and circuits outlined pro- I 1 v1de for posltlve movementin one direction one direction causes first the starting of aventilating fan, then the introduction of three heating coils'i'nseries, subsequently the introduction of-two coils in series and one inor. the other of a controller member, respon-- 'sive to thermal changes.The movement in parallel and lastly introducing all of the coils inparallel with the line. The reverse movement of the controller firstcuts out the coils connected in parallel and connects two' in series andone in-parallel, the. next step cutsthem all in series, the next stepcutting out the coils entirely and the last" step cutting ogt. the fan.As a result we have a system which automatically cares for itself andpositions the controller at the proper point in direct changes' Whereaswe in Fig.4 appliances for the practice of our invention we will nowdescribe mechanisms response to temperature which are well adapted forthe commercial embodiment of our invention, and some of which we believeto be novel. -In Figs-10 and 11 we have have shown diagrammaticallyshown a particular form of thermostat which we prefer I to use. Thiscomprises a base 126 of some suitableinsulating material, upon the lowerend of which is mounted a pivot pin carrying an L shaped arm 29. Thisarm may be of sheet metal and is provided at the endof the shorter legwith an aperture 127 in which is connected one end of a spring 128, theother end of which is connected to a pin 129* secured to the base 126'.Thespring is normally in tension and tends to throw the longer leg ofthe arm to the left.

The upper end of the arm 29 is slotted out as at 130, to receive a rod131 of less width than the slot and upon the upper end of which ismounted a wheel 30. The lower end of the rod 131 is guided and held inits plane of movement by the strip 132 bent around and secured to arm 29near the bottom of slot 130. Cross bars 133 extend across the open endof the arm 29 and carry the upper end of the spring 134, the lower endof which is connected to 'a pin extending through the lower end of rod131. The spring is normally in tension tending t6 force the arm up andconsequently pressing the wheel 30 against a series of pins numbered 31to 39 inclusive, every other one of which, as already described forms aterminal contact for one of the wires. 77, 78, 113, 114, and 115, theother ends of which are connected with the controller. The motion of thespring pressed roller contact from one live pin to another is quickand-positive in movement due to the pressure of the spring, togetherwith the side motion of the arm 131 within thefslot 130 and sparking andwearingtaway of the contacts is prevented.

. order to insure the proper movement of the arm 29 in response tothermal changes we have provided a long tube 135 made of some, suchmaterial as hard rubber,'having a high coeflicient of expansion, withits lower end abutting against a lug 136 pivoted to the shorter end ofthe L shaped arm 29 intermediate the pivot point 40 and the aperture127. The upper end of the tube 135 abuts against a fixed rod 137, theupper end of which is threaded and secured in position on the lug 139 bythe-lock nuts 138. In order that the tube 135 may be held in properposition in alinement wtih the rod 137 and the lu 136, we inclosethesame in a metallic tu e 140, the lower end of which is pinned to the lug136 and the upper-end of which slidably engages the exterior of the rod137 It is obvious that an elongation of the tube 135 due to an increasein temperature will cause movement of the roller or wheel 30 to theright across the contacts 39, 38, 37, 36,

35, 34 and33. A shortening of the rod, due

to contraction responsive to a lowering of the temperature permits thespring 128- to throw the arm .29 with its roller 30 backward across thecontacts in reverse order;

nets.

In Figs. 5, 6, 7 and 8 is illustrated a speclfic controller mechanismfor actuating the fan motor and heating coil circuits in response to thethermostat. .The numeral 141 represents abase or support of suitableinsulating material within an opening 143, in

which isslidably mounted the carriage 45,-

. the frame and sliding carriage in the same relation as shown in Fig.4. The contacts Y 67 and 68 are short rods of conducting materialpositioned vertically in openings formed in the sliding carriage whichis of a suitable insulating material.

' On the opposite side of the frame from that carrying the springfingers69 to 76, are positioned the spring fingers 58 to 64 inclusive,contacting with the slide bars 56 and 57 mounted on the carriage.

.At each end of the opening 143 in the frame are mounted the actuatingmagnets 46 and .47 in front of which are positioned the slidingarmatures 48 and 48. These armatures are carried by the rod 52-52 whichin turn are slidable within the supports 144,

145 and 144 and 145, which carry the mag- At the other ends of the rods52 and 52 are positioned the single throw switches 53 and 53 alreadydescribed in connection with the wiring diagram in Fig. 4. The

switch members 53 and 53 are pivoted to the support at 146 and 146 andcarry at their inner ends yokes 147 and 147 The outer ends of the rods52 and 52 are threaded to receive elongated nuts 142 and 142- which aredrawn by the springs 49 up into contact with the magnet supports 144 and144.

-Adjustment of-the nuts 142 and 142 permits variations in the length ofthrow of pawls 50 and 50'. Depending arms 148 and 148 of insulatingmaterial are carried on the ends of the'rods 52jand 52 between thenuts/142, 142 and lock nuts 142, 142". ,The lower ends of the 'arms'l'48'and 148 extend between the finger of the yokes 147 and 147 andinto slots 148 and 148 in the'base.

The engagement of the downward extending arms in the slotsprovides'proper guidance for the armatures holdingthem horizontal.

The yokes permit of a slight lost motion so that the armatures onapproaching their magnets are permitted. to acquire suflicient velocityto carry the ratchet 50 or '50 over the ratchet teeth before throwingthe switches 53 or 53 deenergizing the magnets.

Brackets 150 and 150 are secured to the frame in front of the armatures48 and 48 to limit their motion toward oneanother.

.These strips have upward extending ears to which are secured the'twoparallel side bars- 152, extending along each side of the ratchet toothbars 51 and 51. The ratchet culiarshapeand are provided with aninterconnecting mechanism whereby when one pawl is drawn back over aratchet tooth, the

. opposite pawl is raised from engagement with its rack so as to permitthe other ratchet on its forward motion under the influence of thesprings to move thecarriage. The active ends of the ratchet pawls 50 and50 are shaped with downward extending thumbs 153 and 153 which engagewith the ratchet teeth 51 and 51 respectively. Extendingupward at anangle to the thumbs .153 and 153 are fingers 154 and 154 terminating at.their ends in downward extending hook parts 155 and 155'. Pins 156 and156' extend outward from each of the pawls near the juncture of thethumbs and fingers and carry on their ends the links 157 and 157 throughengagement with the slots 158 and 158 The forward ends of the links 157and 157 carry inward projecting dogs 159 and 159 which extend into theopenings formed by the thumbs 153, 153 and hooks 155ml 155. The dogs 159and "159 also carry short levers 160 and 160 which extend backward atacute angles to the links 157 and 157 terminating in pins 161 and 161pivoted in the side rails 152- The operation of the ratchet pawls is as;

follows. Supposing for example that the .magnet 46 is energized drawingbackward the armature 48, the first rearward move ment of the pawl 50.will carry the thumb 159 upward on the inclined tooth of the ratchet 51untilthe pin 156 reaches the end of the slot .158.- This point will bejust prior to the dropping of the-thumb'158 over the top of one of theratchet teeth. On engagement of the'pin 156 with the end of the slot 158the link 157 is drawn backward pivoting on the pin 161 and raising thedog 159. Thenpward movementof thedog 159 causes its engagement with thefinger 154 with the result that the ratchet pawl 50 with its operatingthumb 153- is raised out of engagement with its ratchet teeth.- Thislifting of the pawl 154' continuesuntil' link .157 throws'dog159pas'tjthej nub 154, the engagement of which holds pawl 154 raised. 7By thist'nne the thumb 153 has dropped down into the next ratchet toothand the armature 48 is ready for retraction. When springs 49 retractthearmature. to move the carriage pin 156' travels the-length of .its-

Zslot, releases the latch dog .159 and allows pawl 50"to dro back intothe next tooth .pocket of its rac c. At the end-of this move lessees-ment the ratchets are both in engagement with their teeth and thecarriage is positively locked against further movement until one of themagnets 46 or 47 is again energized. i

The springs 49 are secured to the movable parts of the armatures 48 and48 by engagement with the ends of the rods 162- heating coils 167 formedfrom'wire having a relatively low coeficient of conductivity.Oneterminal of each heating coil 167 is secured to asuitably formedinsulator and extends outward adjacent the rod 164. The convolutions ofthe first coil, as illustrated in Fig. 3, extend outward around thecurves of the frame in a plane at right angles to the axis of the rod164 to a point 168 at its outer end. At this point the coil is bent overparallel with rod 164 to a point somewhat removed from the first sectionand there extends inward in a series of coils down to the rod 164. It isthen carried along the rod 164 around a suitable insulating sheath 169and again run outward around theconformation of the frame to form asecond unit.

This method of forming the heatingcoils is so flexible and simple thatthe required length of Wire for properly heating the air passingthrough'thedu'ct 17 is readily placed the embodiment of the inventionshown three sets of coils X, Y- and Z are used.

Each 'set of coils'maycomprise any number. of spirals, and it is obviousthat more or within the'enlargement of the duct 17 In v scribed" it isevident that various changes- 'may made in order to adaptitto particularenvironments." In. some instances it may be found necessary to use alarge num-' her-of heating units and consequently use.

a controller having morethan five steps or I jumps to operate the units.Again in some instances 1t may be found desirable to locate thethermostat withinthe area to be heated j and "ventilated, though we havefound that in street car work or infact in any work where. thecompartment to be heated is;

poorly insulated from the surrounding at .mosphere', it is mostdesirable to have the thermostat exposed to the outside tempera:

ture in order to properly condition or prepare the interior for changesdue to outside temperature changes. Whereas in the system shown theventilating fan is connected through the controller, in some instancesit may be advisable to bridge over a circuit for the fan so as to permitits operation independent of the thermostat.

ereas We have illustrated and described a particular embodiment of ourinvention, it is obvious that various changes in the wiring and in thearrangement of controller contacts may be made without departing fromits spirit and scope.

Having described our invention, what we claim is p 1. In an automaticheat controlling system, the combination of an arm movable to variouspositions in .response to thermal changes, a plurality of contact pointsin the path of said arm, a controller having a movable part, meansresponsive to the engagement of said arm with the contact points formoving said controller part from one position to another, a source ofcurrent supply, electrical heating coils and switches operated-by themovement of said controller for connecting said coils in variousrelations to the line. I

2. In an automatic heat controlling system, the combination of an. armmovable to various positions in response to thermal changes, a pluralityof contact points in the path of said arm adapted to be progressivelyengaged thereby, a controller having a part movable step by step ineither direction; means responsive to the engagement of said arm withthe. contact points for moving said controller part step by step fromone posi tion to another, a source of current supply, a plurality ofelectrical heating coils, and switches operated bv the movement of saidcontroller part for connecting said coils in various relations to thesource of current supply. 7

.3. In an automatic heat controlling system, the combination of an armmovable to varying positions in response to thermal changes, a pluralityof contact points in the path of said arm, .and adapted to be progressively engaged thereby, a controller having an electro-magneticallycontrolled part movable step by step in either direc tion, circuitsincluding said arm and contacts for operating the electro-magneticallycontrolled part, a source of current supply, electrical heating coils, aplurality of switches operated by the movement of said controller partfor connecting the coils in various relations to the source of currentsupply.

4:. In an automatic'heat controlling sys tem, the combination of athermostat, a controller having a movable part, means connected with thethermostat for moving said controller part in response to thermalchanges, a ventilating fan motor, a series of heating coils in thedischarge duct of said fan and switches operated by the movements ofsaid controller part for connecting the said fan motor and heating coilsin circuit with a source of current supply.

5. In an automatic heat controlling sys-' tem, the combination of athermostat, a controller having a movable part, meansconnected with thethermostat for moving said controller part in response to thermalchanges, a ventilating fan motor, heating coils in the discharge duct ofsaid fan and switches operated by the movements of said controller partsfor connecting said fan motor and heating coils in circuit with a sourceof current supply, said switches being arranged to include the fan motorin circuit the heating coils are in circuit.

6. In an automatic heat controllingsystem, the combination of athermostat, a controller having a slidable carriage, electric motorsoperatively connected with the said -with the source of current supplywhenever carriage for moving it from one position to' another, aplurality of contact points adapted to be'engaged by said thermostat inits 1 from one position to another, means for mo mentarily energizingsaid'electro-responsive meansin response to movement of the. saidthermostat, a plurality of heating coils, I

contact fingers positioned adjacent the carriage and connected to. thesaid coils, contact fingers similarly placed and connected with a sourceof current supply, and-contact strips movable with said can-riagejand:

adapted to engage with the said fingers and cut the said coils in or outof the source of current supply.

In ,an' automatic heat controlling sys tem, the combination of athermostat, a controllerl having a movable part, electro-responsivemeans for moving said movable part of the controller in response tomovements of the thermostat, a fan operating.

motor, a plurality of heating coils, positioned in the discharge ofthefan, a source said controller moving part, whereby movejment'of thecontroller part one direction of current supply, switches operated bythe.

' first connects the fan motor with the source of supply, then the coilsin series and lastly the coils in parallel.

9. .In an automatic heat control system, the combination ofa controllerhav1ng a slidable carriage, electro-responsive means for moving the saidcarriage in a step by step motion, a thermostat having progressiveengagement with a plurality of contact plns, electrical connectionsbetween the said pins and a series ofcontact fingers adjacent thesliding carriage; a source of current supply, contacts on the saidcarriage adapted to engage all'but one of the said fingers andconnections between the said contacts and the electro-responsive means.

10. In an automatic heat control system,

rality of strips extending outward in spiral formation from the'rod, andspaced from each other, insulating rods; parallel to the supporting rodand carried by said strips, and electrical heating wires carried by thesaid insulating rods.

12. In an automatic heat controlling system a movable member, heatingmeans controlled by said member for increase or decrease of heatingeffect as said memiber moves in one direction or the other,electroresponsive means for imparting step by step movement to saidmember-in either direction, and a thermostat controlling saidelectro-responsive means.

13. In an automatic heat controlling system, a movable member, heatingmeans controlled thereby for increase or decrease of the heating efiectas said member moves in one direction or the other, electro-responsivemeans for imparting step by step movement to said member in eitherdirection, switches controlled by movement of said member, a thermostathaving a movable contact and a plurality of temperature indicatingcontacts, and circuit connections for said electro-responsive meansgoverned by the thermostat contact and controlled by said switches forconnecting all temperature contacts on one side of the movable contactto operate said step by step means in one direction and on the otherside of the movable contact to operate said step by step meansi the oposite direction.

14L. ii an automatic heat controlling system for street cars or thelike, the combination of a thermostat positioned outside of the car, acontroller having a movable part, means connected with the thermostatfor moving said controller in response to outside thermal changes, aventilating fan having inlet and discharge ducts, a motor for drivingsaid fan, a series of heating coils in the discharge duct of said fan,the inlet duct opening outside the car, and switches operated by themovements of said controller part for connecting the said fan motor andheating coils in circuit with a source of current supply.

15. In an automatic heat controlling system for street cars or the like,the combination of a movable member, heating means within the carcontrolled by said member for increase or decrease of heating effect assaid member moves in one direction or the other,

' electro-responsive -means for impartingstep by step movement to saidmemberin either directlon, and a thermostat positioned outside of thecar and controlling said electroresponsive means.

In testimony whereof we hereunto set our hands.

JOHN K. NORSTROM. GEORGE O. BREIDERT. In the presence of STANLEY'W.COOK, MARY F. ALLEN]

